Measuring adsorption equilibria: The determination of the maximum binding capacity depends strongly on the method of resin preparation

Accurate determination of adsorption isotherms is critical for designing chromatographic separations and selecting resins based on maximum binding capacity for the target molecule. This study evaluates different methods for preparing chromatography resins for batch adsorption isotherm experiments, comparing a volumetric slurry-based method, weight-based methods using vacuum filtration and centrifugation, and a commercial PreDictor^TM Isotherm plate to capacities observed in column operation. The results show that weighing of hydrated particles after centrifugation, combined with density measurement provides the most accurate and reproducible binding capacity values, closely matching breakthrough data. This study highlights the importance of resin preparation methods in batch adsorption experiments and recommends the centrifugation method for non-automated workflows, as it provides the most reliable prediction of maximum binding capacity observed in column experiments. These findings are consistent for both anion- and cation-exchange resins with different resin backbones. This suggests the broad applicability of the proposed approach.